Common Bugs with Debugging (Yes, Really)
Meta-bugs: things beginners do while debugging that make debugging harder.
From Bee: "I see this exact bug in beginners every week. Read it once, and you'll spot it on yourself before it bites."
Changing two things at once
txt
Bug. Add try/catch + change algorithm. Now works. Why? No idea.⚠️
Why this happens
You can't tell which change fixed it. The other change might be hiding a different bug.✅
The fix
Change one thing at a time. Test. Then change the next.Skipping the error message
txt
"It just doesn't work" — without quoting the actual error.⚠️
Why this happens
The error often spells out the answer. Beginners panic and don't read it.✅
The fix
Read the LAST line first (the actual error), then walk up the stack trace for context.Modifying production data while debugging
txt
console-edit a record on prod to "see what happens"⚠️
Why this happens
Now your data is wrong AND you've lost the ability to reproduce the bug.✅
The fix
Reproduce locally first. Touch prod data only with intent and a backup.Forgetting to remove print statements
js
console.log("DEBUG", user);
// ships to production⚠️
Why this happens
Logs leak data and clutter logs in prod.✅
The fix
Use a logger with levels (debug/info/warn) and disable debug in prod. Or grep before commit.Believing "it works on my machine"
txt
Local: works. CI: fails. "Must be CI's fault."⚠️
Why this happens
Usually a difference in env vars, file paths, locale, dependency versions, or DB seed data.✅
The fix
Reproduce in a clean container. The difference between "works locally" and "fails in CI" is real configuration.💡
Want the full lesson?
Read Debugging — the complete lesson, or test yourself with the quiz.